HVAC glossary: the terms on your quote, explained.

In a Wisconsin climate, a condensing furnace at 95% AFUE or above is the sensible default, and 80% only makes sense in specific venting situations. AFUE is the share of the fuel you buy that becomes heat in the house, so an 80% furnace sends roughly a fifth of your gas bill out of the flue while a 95% furnace sends about a twentieth. Over a heating season here that difference is real money. More on furnaces here.

SEER2 is the current cooling efficiency rating and it replaced SEER in 2023 under a tougher test procedure that accounts for realistic duct resistance. Because the test is harder, the same machine scores a lower number under SEER2 than it did under SEER, so comparing a SEER2 figure against an old SEER figure will mislead you. Compare SEER2 to SEER2 only.

MERV 8 to 13 suits most homes, and higher is not automatically better. A denser filter catches more but also resists airflow more, and fitting a high-MERV filter to a system that was not designed for it starves the blower, raises static pressure and can cause the very problems you were trying to solve. If you want serious filtration, the right answer is usually a properly sized media cabinet rather than a thicker filter in the existing slot. More on air quality here.

The only honest answer comes from a Manual J load calculation on your specific house, which accounts for square footage, insulation, windows, orientation and air-tightness. Copying the capacity of the existing unit is the most common shortcut in the trade and it perpetuates whatever mistake was made last time. Oversizing in particular causes short cycling, poor humidity control and shorter equipment life.

R-454B is the low-global-warming-potential refrigerant now going into new residential equipment, including Carrier's. It is an A2L classed refrigerant, meaning mildly flammable, which brings different handling and installation requirements. Existing R-410A systems keep running and can still be serviced, but the two are not interchangeable and R-410A will become more expensive over time.

Short cycling is when a system runs for only a few minutes, shuts off, and restarts soon after, and it is worth chasing down. It is a symptom rather than a fault: the usual causes are a clogged filter, a restricted duct system, a failing sensor or limit switch, or equipment oversized for the house. Left alone it wastes energy, leaves the house unevenly heated or cooled, and wears out components that hate frequent starts. Furnace repair here.

Both exhaust stale indoor air and bring in fresh outdoor air while recovering energy from the outgoing stream; the difference is that an HRV transfers heat only, while an ERV transfers moisture as well. In a cold, heating-dominated climate an HRV is often enough, but where summer humidity is also a problem — which describes most of the Sheboygan lakeshore — an ERV is usually the better fit.

Static pressure is the resistance your duct system puts up against the air the blower is trying to move, measured in inches of water column. Most residential equipment is designed around roughly 0.5 in. w.c., and plenty of real houses run well above it, especially older ones whose ducts were built for a slow-moving gravity furnace. Installing modern equipment without measuring it produces noise, uneven room temperatures and premature blower failure, which is why we take the reading before we quote.